Damping type composite modified asphalt, preparation method and damping property evaluation method of damping type composite modified asphalt

Abstract

The invention relates to the technical field of road asphalt materials, in particular to damping type composite modified asphalt, a preparation method and a damping property evaluation method of the damping type composite modified asphalt. The composition formula of the damping type composite modified asphalt is developed and disclosed by integrating viscous damping response and elastic recovery response as evaluation indexes of the damping performance of the asphalt, 100% of matrix asphalt is used as a carrier, 10-30% of butyl reclaimed rubber RIIR, 1.5-4% of an SBS modifier and 0.1-0.3% of a stabilizer are used, so that the damping noise reduction performance of the composite modified asphalt is improved, and the pavement performance is guaranteed. Meanwhile, the invention discloses a preparation method of the damping type composite modified asphalt, three stages of stirring swelling, high-speed shearing and heat preservation development and process parameters are designed, a practical engineering application foundation is laid, and meanwhile, technical support is provided for reducing tire-pavement action noise from the field of pavement materials.

Description

Technical Field

[0001] The present application relates to the technical field of road asphalt materials, and in particular to a damping type composite modified asphalt, a preparation method and a damping property evaluation method thereof. Background Art

[0002] The damping performance of a pavement refers to the ability of the pavement to dissipate energy during the tire-pavement interaction. The damping principle of pavement materials is related to their dynamic mechanical relaxation characteristics. Under the action of a vibrating object, the material absorbs a certain amount of vibration energy and converts it into heat energy or other forms of energy that can be lost. The result is a damping effect that attenuates vibration and vibration transmission. Asphalt, as a viscoelastic material, has certain damping properties. By reducing the transmission of vibration in the pavement structure, the vibration energy is dissipated, thereby achieving the purpose of noise reduction. At the same time, asphalt plays a decisive role in the damping performance of the mixture. Therefore, the research and development of damping-type composite modified asphalt will greatly improve the damping performance of the pavement, thereby promoting the development of new low-noise pavements.

[0003] Rubber and rubber-modified asphalt have excellent damping properties and elastic characteristics. As a damping asphalt, rubber asphalt is still a hot topic in the research of noise-reducing asphalt binders. Although rubber-modified asphalt has certain applications in pavement noise reduction, there are problems such as thermodynamic incompatibility between rubber powder and modified asphalt. At the same time, the presence of rubber particles causes serious damage to the performance of the pavement during actual use, which greatly limits its actual engineering application. Summary of the invention

[0004] In order to develop a damping type composite modified asphalt with excellent damping performance and guaranteed road performance, and to solve the current problem of the contradiction between the noise reduction function and road performance of asphalt binder, the present application provides a damping type composite modified asphalt and a preparation method thereof.

[0005] On the one hand, the present application analyzes, screens and tests the raw materials, and finally determines that recycled butyl rubber RIIR is used as a damping modifier. The SBS composite RIIR modification technology is used to select the best composition ratio according to the target requirements, and finally develops a damping composite modified asphalt with improved damping and noise reduction performance and guaranteed road performance that meets specific technical indicators. The damping composite modified asphalt provided in the present application adopts the following technical solution: A damping type composite modified asphalt, calculated by mass percentage of base asphalt, comprises the following components: Base asphalt 100%; Butyl reclaimed rubber RIIR 10~30%; SBS modifier 1.5~4%; Stabilizer 0.1~0.3%.

[0006] Optionally, the base asphalt is Sinopec 70# base asphalt.

[0007] Optionally, the preparation steps of the butyl regenerated rubber RIIR include: recycling and crushing the butyl inner tube, and then subjecting it to a regeneration and desulfurization process to obtain the butyl regenerated rubber RIIR.

[0008] Optionally, the SBS modifier is a linear YH-791 type with a block ratio (S / B) of 30 / 70.

[0009] Optionally, the stabilizer is industrial sulfur with a sulfur content of 99.98% and a fineness of 800 mesh.

[0010] By adopting the above technical scheme, butyl rubber IIR is copolymerized by the main monomer isobutylene and a small amount of auxiliary monomer isoprene, and is a linear polymer copolymer. There are only a small amount of unsaturated bonds on the molecular chain segment, and the main chain is almost saturated, with good thermal stability and chemical stability. And almost every link of the main chain is tightly surrounded by two methyl groups, the molecular structure is tight, and the friction between the molecular chains during the relaxation of the chain segment is very intense, resulting in a large energy loss. It has excellent characteristics of absorbing vibration and dissipating energy, and is an ideal choice for the production of damping materials. SBS is a styrene (S)-butadiene S2, shear:-styrene (S) block copolymer. The polymer chain of the linear SBS has a series structure with different blocks including plastic segment B and elastic segment S. There is no chemical bond between the molecules, but they are connected by van der Waals force and hydrogen bonds between molecules. Under the influence of external factors such as temperature, the molecular chains can slide against each other, and have good ductility and flexibility. The butadiene on the main chain of the SBS molecule has unsaturated double bonds, which improves its damping energy dissipation capacity. The introduction of a benzene ring with large steric hindrance on the side group significantly increases the elastic hysteresis effect of the molecular structure, which is the essence of its good damping properties.

[0011] Therefore, the present invention is based on the research of the research group for many years on the technical basis of pre-desulfurization of waste oil to prepare stable rubber asphalt, and selects the RIIR after regeneration and desulfurization as a damping type modifier. On the one hand, after mechanical desulfurization and regeneration of butyl rubber IIR, its internal cross-linked network is destroyed, and part of the main molecular chain of rubber is also broken, and the relative molecular mass is reduced, which causes it to be subjected to external force. The friction between molecules increases, and the energy applied by the outside world is converted into heat energy, and the damping effect is played to a greater extent. On the other hand, the compatibility of the RIIR treated by regeneration and desulfurization and the asphalt system is improved. Further utilize the SBS composite RIIR modification technology to realize the research and development of damping type composite modified asphalt, and develop a damping type composite modified asphalt with excellent damping performance and taking into account noise reduction function and road performance.

[0012] In the second aspect, the present application provides a method for preparing a damping type composite modified asphalt, and designs specific steps and process parameters of three stages: stirring swelling, high-speed shearing, and heat preservation and development, including: S1. Swelling: Heat the base asphalt to a molten state, add the weighed SBS modifier to the base asphalt and raise the temperature to 180° C., use a stirrer to stir at a rate of 200-500 r / min for 20-40 min to allow the modifier to fully swell, and obtain a mixture of the SBS modifier and the base asphalt; S2, shearing: the temperature is still 180 ° C, and the mixture of the SBS modifier and the matrix asphalt is sheared at a high speed of 3000-4000 r / min for 30-50 min using a high-speed shearing machine; then, the temperature is kept unchanged, a stabilizer is added in small amounts and multiple times, and after stirring evenly, a low-speed shearing is performed at a rate of 2000 r / min for 10-30 min. After the shearing is completed, the sheared asphalt is obtained; S3, development: the sheared asphalt is moved to a 180°C oven, kept warm, and swelled and developed for 30-90 minutes to obtain a damping type composite modified asphalt, which lays a foundation for the practical engineering application of the damping type composite modified asphalt.

[0013] Optionally, the stirring time in step S1 is 30 minutes.

[0014] Optionally, the high-speed shearing rate is 4000 r / min, and the shearing time is 35 min; the low-speed shearing time is 15 min.

[0015] Optionally, in step S3, the time for the modified asphalt to be kept warm and swelled in the oven is 45 minutes.

[0016] On the third aspect, the present application provides a damping evaluation method for evaluating the damping performance of the above-mentioned damping type composite modified asphalt, involving damping viscous response and damping elastic response; obtaining the damping factor temperature curve of the material to be tested through a temperature scanning test, reflecting the damping viscous response of the material to be tested; characterizing the elastic recovery rate of the material to be tested at normal use temperature, reflecting the damping elastic response of the material to be tested.

[0017] Through the above technical scheme, the present invention aims at the particularity that the starting point of the development of the asphalt of this application is excellent damping performance, takes significantly improving the damping characteristics of asphalt as the core goal, and proposes an evaluation method with damping performance as the key evaluation indicator.

[0018] The specific technical indicators of the evaluation method include damped viscous response and damped elastic response, which are characterized by the damping factor temperature curve of asphalt and the elastic recovery rate at normal use temperature obtained through temperature scanning tests respectively.

[0019] The research and development of damping-type composite modified asphalt is achieved through the SBS composite RIIR composite modified asphalt technology, and the synergistic effect of stabilizer and damping-type modifier is further utilized to make the composite modified asphalt meet specific technical indicators, that is, the damping and noise reduction performance is improved and the road performance is guaranteed.

[0020] In addition, the evaluation of road performance refers to the current needle penetration evaluation method in my country and the representative SHRP evaluation method worldwide, and the high and low temperature performance of damping type composite modified asphalt is experimentally studied from the perspective of rheology.

[0021] In summary, the present application includes at least one of the following beneficial technical effects: 1. The present invention selects RIIR after regeneration and desulfurization as a damping modifier. On the one hand, after the butyl rubber IIR is regenerated by mechanical desulfurization, its internal cross-linking network is destroyed, and part of the rubber main molecular chain is also broken, and the relative molecular mass is reduced, resulting in an increase in the friction between molecules when it is subjected to external forces, converting the energy applied by the outside into heat energy, and exerting a damping effect to a greater extent; on the other hand, the compatibility of the regenerated desulfurized RIIR and the asphalt system is improved; further using the SBS composite RIIR modification technology, the research and development of damping composite modified asphalt is realized, and a damping composite modified asphalt with excellent damping performance and taking into account both noise reduction function and road performance is developed; 2. In view of the particularity that the starting point of the development of the asphalt of this application is excellent damping performance, the present invention takes significantly improving the damping characteristics of asphalt as the core goal, and proposes an evaluation method with damping performance as the key evaluation index. The specific technical indicators of the evaluation method include damping viscosity response and damping elastic response. The damping factor temperature curve of asphalt and the elastic recovery rate characterization at normal use temperature are obtained through temperature scanning tests respectively; the research and development of damping-type composite modified asphalt is realized through the SBS composite RIIR composite modified asphalt technology, and the synergistic effect of stabilizer and damping-type modifier is further utilized to make the composite modified asphalt meet specific technical indicator requirements, that is, the damping and noise reduction performance is improved, and the road performance is guaranteed. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the damping viscosity response of Examples 1 to 4 of the present application and Comparative Example 1.

[0023] Figure 2 It is a schematic diagram of the elastic recovery response of Examples 1 to 4 of the present application and Comparative Example 1. DETAILED DESCRIPTION

[0024] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. The following embodiments are only illustrative and not restrictive, and the protection scope of the present invention cannot be limited thereto.

[0025] The materials, methods and examples in the examples of the present application are exemplary and should not be construed as limiting unless otherwise specified.

[0026] A damping type composite modified asphalt, calculated by mass percentage of base asphalt, comprises the following components: base asphalt 100%, butyl reclaimed rubber RIIR 10-30%, SBS modifier 1.5-4%, stabilizer 0.1-0.3%. In the following embodiment: The base asphalt is Sinopec 70# base asphalt; the rubber hydrocarbon content in RIIR is 55%; SBS is linear YH-791 type, and the block ratio (S / B) is 30 / 70; the stabilizer is industrial sulfur, with a sulfur content of 99.98% and a fineness of 800 mesh, meeting the requirements of high-quality products.

[0027] In the following embodiments: 1) The present invention obtains a damping factor temperature curve through a temperature scanning test to characterize the viscous damping response of asphalt, and characterizes the elastic recovery response through a 25°C elastic recovery test.

[0028] 2) The temperature scanning range of the temperature scanning test in step 1) is 40~130℃, the temperature increment is set to 10℃, the parallel plate diameter is 25 mm, and the plate spacing is 1 mm. The test applies a continuous sinusoidal alternating load, adopts a strain control mode, and a fixed frequency of 10 rad / s to simulate the state of a vehicle speed of about 80 km / h on an asphalt pavement. Since the average maximum temperature of asphalt pavements in most parts of my country in summer varies between 50~70℃, considering the influence of unfavorable conditions such as heavy traffic on high-grade highways, the viscous damping response of asphalt binders in the temperature range of 40~80℃ is analyzed. The specific operation refers to the "Test Procedures for Asphalt and Mixtures in Highway Engineering" T0628-2011 and is carried out in accordance with AASHTO T315-22.

[0029] 3) The elastic recovery test described in step 1) uses a ductility test instrument and a test mold, and the middle part is replaced with a straight side mold. It is carried out under 25°C water bath conditions. The asphalt sample is pulled to (10±0.25) cm at a tensile rate of 5 cm / min and stopped, and quickly cut from the middle part. The sample is kept in a 25°C water bath for 1 hour, and then the residual length of the specimen is measured and its elastic recovery rate is calculated. The specific operation refers to the "Highway Engineering Asphalt and Mixture Test Procedure" T0622-2011.

[0030] 4) The present invention adopts the Multiple Stress Creep Recovery (MSCR) test to evaluate the high temperature performance of the asphalt binder, adopts the Bending Beam Creep Tester (BBR) to test the low temperature fracture characteristics of the asphalt binder, and adopts the Brookfield viscosity test to evaluate the construction and workability of the modified asphalt.

[0031] 5) The specific operation of MSCR described in step 4) is carried out according to AASHTO T350-19 and ASTM D7405 standards. The test temperature is 64 ° C, and a 25 mm parallel plate is selected with a gap of 1 mm. The stress levels are selected to be 0.1 kPa and 3.2 kPa for continuous testing, and 10 loading-unloading cycles are performed at each stress level, each cycle including 1 s of loading creep and 9 s of unloading recovery.

[0032] 6) The BBR test operation described in step 4) refers to the "Highway Engineering Asphalt and Mixture Test Procedure" T0622-2011, the specimen size is 12.7 mm × 6.35 mm × 12.7 mm, the control test contact load is 35 mN ± 10 mN, and the initial test load is 980 mN ± 50 mN. The test was carried out at -12℃, -18℃, and -24℃. The low-temperature creep stiffness modulus S and creep rate m at the 60th second of the test process were selected to characterize the low-temperature deformation resistance of asphalt. In order to ensure that the asphalt binder does not crack and damage under low temperature conditions, S ≤ 300MPa and m ≥ 0.300 should be met.

[0033] 7) The Brookfield viscosity test described in step 4) tests the apparent viscosity of asphalt at 180°C. For specific operations, refer to the "Highway Engineering Asphalt and Mixture Test Procedure" T0622-2011. During the test, a small amount of asphalt is injected into the aluminum tube, and then vertically insulated at the required test temperature for 1.5 hours. After the asphalt is completely dissolved, the spindle rotor is immersed and the test is started. The torque reading is kept within the range of 10%~98% for measurement. The 180°C Brookfield viscosity test results can provide important reference for the engineering application and quality control of asphalt.

[0034] Example 1 The damping type composite modified asphalt provided by the present invention is obtained by the following preparation method: S1. Swelling: Heat the base asphalt to 160°C to make it molten, add 1.5% SBS modifier to the base asphalt and raise the temperature to 180°C, stir at 300 r / min for 20 min using a stirrer. Then add 15% RIIR and stir at the same rate for 10 min to ensure that the modifier is fully swollen.

[0035] S2. Shearing: Raise the temperature to 180°C and use a high-speed shearing machine to shear the mixture of modifier and base asphalt at 4000 r / min for 30 min. Keep the sample preparation temperature unchanged, add 0.2% stabilizer in small amounts and multiple times, stir evenly, and then shear at 2000 r / min for 20 min.

[0036] S3. Development: The sheared asphalt is moved to a 180°C oven, and is kept warm and swelled for 60 minutes to obtain a damping-type composite modified asphalt.

[0037] Example 2 The damping type composite modified asphalt provided by the present invention is obtained by the following preparation method: S1. Swelling: Heat the base asphalt to 160°C to make it molten, add 3% SBS modifier to the base asphalt and raise the temperature to 180°C, stir at 300 r / min for 20 min using a stirrer. Then add 15% RIIR and stir at the same rate for 10 min to ensure that the modifier is fully swollen.

[0038] S2. Shearing: Raise the temperature to 180°C and use a high-speed shearing machine to shear the mixture of modifier and base asphalt at 4000 r / min for 30 min. Keep the sample preparation temperature unchanged, add 0.15% stabilizer in small amounts and multiple times, stir evenly, and then shear at 2000 r / min for 20 min.

[0039] S3. Development: The sheared asphalt is moved to a 180°C oven, and is kept warm and swelled for 60 minutes to obtain a damping-type composite modified asphalt.

[0040] Example 3 The damping type composite modified asphalt provided by the present invention is obtained by the following preparation method: S1. Swelling: Heat the base asphalt to 160°C to make it molten, add 1.5% SBS modifier to the base asphalt and raise the temperature to 180°C, stir at 300 r / min for 20 min using a stirrer. Then add 20% RIIR and stir at the same rate for 20 min to ensure that the modifier is fully swollen.

[0041] S2. Shearing: Raise the temperature to 180°C and use a high-speed shearing machine to shear the mixture of modifier and base asphalt at 4000 r / min for 30 min. Keep the sample preparation temperature unchanged, add 0.15% stabilizer in small amounts and multiple times, stir evenly, and then shear at 2000 r / min for 20 min.

[0042] S3. Development: The sheared asphalt is moved to a 180°C oven, and is kept warm and swelled for 60 minutes to obtain a damping-type composite modified asphalt.

[0043] Example 4 The damping type composite modified asphalt provided by the present invention is obtained by the following preparation method: S1. Swelling: Heat the base asphalt to 160°C to make it molten, add 3% SBS modifier to the base asphalt and raise the temperature to 180°C, stir at 300 r / min for 20 min using a stirrer. Then add 20% RIIR and stir at the same rate for 20 min to ensure that the modifier is fully swollen.

[0044] S2. Shearing: Raise the temperature to 180°C and use a high-speed shearing machine to shear the mixture of modifier and base asphalt at 4000 r / min for 30 min. Keep the sample preparation temperature unchanged, add 0.15% stabilizer in small amounts and multiple times, stir evenly, and then shear at 2000 r / min for 20 min.

[0045] S3. Development: The sheared asphalt is moved to a 180°C oven, and is kept warm and swelled for 60 minutes to obtain a damping-type composite modified asphalt.

[0046] Comparative Example 1 This comparative example provides a conventional rubber powder modified asphalt, the rubber powder adopts a common binder rubber, and the rubber powder content is the same as the butyl reclaimed rubber RIIR in Example 3, which is 20% of the asphalt mass. The preparation method is the same as that in Example 3, and the specific process parameters are adjusted according to the actual situation.

[0047] The present invention uses rubber modified asphalt, the most commonly used binder for low-noise pavement, as a comparative example, and aims to develop a damping-type composite modified asphalt with excellent damping performance and guaranteed road performance, so as to solve the current technical problem of the contradiction between the noise reduction function of asphalt binder and road performance.

[0048] Performance Evaluation 1. Damping performance evaluation The present invention evaluates the damping performance of the damping type composite modified asphalt prepared in Examples 1 to 4 and Comparative Example 1.

[0049] Viscous damping response The damping viscosity responses of Examples 1 to 4 and Comparative Example 1 are shown in Figure 1 .

[0050] from Figure 1It can be seen that, compared with the comparative example, Examples 1 to 4 provided by the present invention have higher damping factor values, and the damping factor temperature curve is insensitive to changes in temperature. In particular, in the normal use of the road surface at a higher temperature of 40 to 60°C, a certain platform area appears, at which time the elastic component in the asphalt system plays a role, showing a good damping viscosity response comparable to or even better than the comparative example.

[0051] Resilient recovery response The elastic recovery responses of Examples 1 to 4 and Comparative Example 1 are shown in Figure 2 .

[0052] from Figure 2 It can be seen that the elastic recovery rates of Examples 1 to 4 provided by the present invention are all higher than those of the comparative example, and ordinary rubber asphalt has extremely excellent elastic recovery ability, which is closely related to the presence of a large number of solid rubber powder particles inside it. When the rubber powder dosage is constant, the distance between ordinary rubber powder particles is relatively close, the contact effect between rubber powder particles is relatively strong, and a relatively large rubber nucleus is also retained, thereby showing good elastic properties of solid rubber powder particles. However, the regeneration and desulfurization treatment makes the rubber powder particles smaller, and the elastic recovery performance of RIIR modified asphalt is damaged. However, the present invention takes the excellent elastic recovery ability of ordinary rubber asphalt as a design goal, and through the SBS composite RIIR modification technology, the elastic recovery performance of the provided embodiments is greatly improved, that is, it shows excellent damping elastic response, which proves that the damping-type composite modified asphalt proposed by the present invention realizes the research and development of asphalt binder that takes into account both damping viscosity response and elastic response.

[0053] 2. Road performance evaluation The present invention evaluates the road performance of the damping type composite modified asphalt prepared in Examples 1 to 4 and Comparative Example 1.

[0054] High temperature performance In this study, high temperature classification of asphalt was carried out based on the MSCR test, with an irrecoverable creep compliance of 3.2 Kpa J nr3.2 The value at the actual service temperature of the pavement is used as a parameter to divide asphalt into four performance levels that meet different traffic volumes, namely: When the standard traffic level (S) is met, J is recommended nr3.2 <4.5kPa -1 ; When heavy traffic level (H) is met, J is recommended nr3.2 <2.0kPa -1 ; When the overweight traffic level (V) is met, J is recommended nr3.2 <1.0kPa -1 ; When the extremely heavy traffic level (E) is met, J is recommended nr3.2<0.5kPa -1 .

[0055] Table 1 lists the J values ​​of Examples 1 to 4 and Comparative Example 1 at 64°C. nr3.2 The value of and its corresponding traffic level.

[0056] Table 1 Traffic levels of the embodiments and comparative examples Rubber asphalt has excellent high temperature performance and is widely used. As shown in Table 1, the rubber asphalt with a dosage of 20% in Comparative Example 1 has a high nr3.2 0.322 kPa -1 , meeting the extremely heavy traffic grade (E). The damping type composite modified asphalt embodiments 1 to 4 provided by the present invention have a J at 64°C. nr3.2 <0.5kPa -1 , all meet the extremely heavy traffic grade (E), and even show high-temperature performance better than rubber asphalt. Therefore, the damping-type composite modified asphalt proposed in the present invention has excellent damping performance while having excellent high-temperature performance, which is in line with the design concept of the present invention and meets the expected requirements.

[0057] Low temperature performance The BBR test results of Examples 1 to 4 and Comparative Example 1 are shown in Table 2.

[0058] Table 2 BBR test results As can be seen from Table 2, within the range of -12°C to -24°C, as the temperature decreases, the stiffness modulus S value of asphalt shows an increasing trend, indicating that asphalt gradually shows brittleness, and the decrease in temperature increases the risk of asphalt cracking. The creep stiffness modulus of the modified asphalt in Examples 1 to 4 meets the requirement of less than 300MPa within the test temperature range, and is at a lower level at a temperature of -12°C to -18°C, indicating that asphalt is not easy to crack and brittle under low-temperature loads, so the damping type composite modified asphalt shows excellent low-temperature performance under the test temperature conditions. At the same time, the creep rate of the damping type composite modified asphalt is maintained at a high level, which means that the asphalt still has a strong ability to relax stress, the stress relaxation time is shorter, and the possibility of cracking is small, so that the modified asphalt can still maintain good ductility at low temperatures.

[0059] Construction and workability The BBR test results of Examples 1 to 4 and Comparative Example 1 are shown in Table 3.

[0060] Table 3 Rotational viscosity results of examples and comparative examples As can be seen from Table 3, the essence of the viscosity index is the internal friction that prevents the relative movement of asphalt. Therefore, higher viscosity is beneficial to the high-temperature deformation resistance of asphalt, but too high viscosity brings difficulties to construction, resulting in problems such as poor construction and workability. In short, the viscosity of the damping composite modified asphalt is within a reasonable range, which provides the possibility of further development for its actual engineering application.

[0061] In summary, the damping type composite modified asphalt of the present application exhibits excellent damping performance and good road performance.

[0062] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A damping type composite modified asphalt, characterized in that: Calculated by mass percentage of base asphalt, it includes the following components: Base asphalt 100%; Butyl reclaimed rubber RIIR 10~30%; SBS modifier 1.5~4%; Stabilizer 0.1~0.3%.

2. A damping type composite modified asphalt according to claim 1, characterized in that: The preparation steps of the butyl regenerated rubber RIIR include: recycling and crushing the butyl inner tube, and then subjecting it to a regeneration and desulfurization process to obtain the butyl regenerated rubber RIIR.

3. The damping type composite modified asphalt according to claim 1, characterized in that: The SBS modifier has a linear structure and a block ratio (S / B) of 30 / 70.

4. The damping type composite modified asphalt according to claim 1, characterized in that: The stabilizer is industrial sulfur with a sulfur content of 99.98% and a fineness of 800 meshes.

5. A method for preparing a damping type composite modified asphalt according to any one of claims 1 to 4, characterized in that: The following steps are involved: S1. Swelling: heating the base asphalt to a molten state, adding the weighed SBS modifier to the base asphalt and raising the temperature to 180° C., stirring to allow the modifier to fully swell, and obtaining a mixture of the SBS modifier and the base asphalt; S2, shearing: subjecting the mixture of the SBS modifier and the matrix asphalt to high-speed shearing, and then adding a stabilizer in small amounts and multiple times, stirring evenly and then shearing at a low speed, and after the shearing is completed, sheared asphalt is obtained; S3, development: the sheared asphalt is moved to a 180°C oven for heat preservation, swelling and development to obtain a damping type composite modified asphalt.

6. The method for preparing a damping type composite modified asphalt according to claim 5, characterized in that: The stirring speed in step S1 is 200-500 r / min, and the stirring time is 20-40 min.

7. The method for preparing a damping type composite modified asphalt according to claim 5, characterized in that: The high-speed shearing rate is 3000-4000 r / min, and the shearing time is 30-50 min; the low-speed shearing rate is 2000 r / min, and the shearing time is 10-30 min.

8. The method for preparing a damping type composite modified asphalt according to claim 5, characterized in that: In step S3, the time for the modified asphalt to be kept warm and swelled in the oven is 30 to 90 minutes.

9. A damping property evaluation method for evaluating the damping property of the damping type composite modified asphalt according to any one of claims 1 to 4, characterized in that: Involving damped viscous response and damped elastic response; obtaining a damping factor temperature curve of the material to be tested through a temperature scanning test, reflecting the damped viscous response of the material to be tested; The elastic recovery rate of the material to be tested at normal use temperature is used to characterize the damped elastic response of the material to be tested.

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